Balloon catheter folding and wrapping devices and methods

ABSTRACT

A balloon folding apparatus is provided for use in the manufacture of balloon catheters. The balloon folding apparatus includes a plurality of arms and a plurality of blades attached to the plurality of arms such that the plurality of blades is capable of translating in a radial direction. Preferably, a plurality of stepper motors coupled to the plurality of arms provides precise radial movement of the plurality of blades. Each of the plurality of blades is profiled to create a plurality of folds in a balloon catheter. A balloon wrapping apparatus is also provided and operates in a similar manner. The balloon wrapping apparatus includes a plurality of blades configured to wrap a folded balloon catheter around a catheter shaft so as to minimize the diameter of the balloon catheter.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119(e) to U.S.Provisional Application Ser. No. 60/637,345 filed on Dec. 17, 2004, theentire content of which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to balloon catheters. Moreparticularly, the present invention relates to devices and methods usedto fold and wrap balloon catheters during the manufacture of suchballoon catheters.

2. Description of the Related Art

A balloon catheter generally comprises an inflatable balloon that ismounted along a distal end of an elongate catheter body (i.e., shaft).Balloon catheters are used by physicians in a wide variety oftherapeutic procedures. In one common use, a folded balloon catheter isadvanced through a blood vessel to a region that has become occluded byatherosclerotic plaque. The balloon is inflated to dilate the occludedregion and thereby improve the flow of blood through the vessel. Inanother common use, an expandable stent is provided along the exteriorof the balloon. The balloon is advanced to the treatment site and isthen inflated to deploy the stent. The balloon is then deflated and theballoon catheter is withdrawn from the patient. The expanded stentremains in the blood vessel to provide support to the vessel wall.

SUMMARY OF THE INVENTION

Embodiments of the present invention disclosed herein provide improveddevices and methods for folding and wrapping balloon catheters. Thepreferred embodiments facilitate the manufacture of balloon catheterswhile minimizing costs and providing a balloon catheter that expands ina reliable and predictable manner. Further, the preferred embodimentsprovide a modular unit that is capable of folding and wrapping ballooncatheters of a variety of different sizes and shapes.

Balloon catheters are typically formed of a very thin, yet strongmaterial. During manufacture, a balloon catheter is folded at a numberof locations along its longitudinal axis. After the balloon is folded ina variety of locations, the folds are wrapped around the catheter toreduce the balloon to a constrained condition having a very smalldiameter. In the case wherein the balloon is used to deploy a stent, thestent is crimped onto the balloon after the folding step. The balloon isadvanced through the blood vessel to a treatment site while in theconstrained condition. The balloon is inflated by directing a fluidthrough a lumen in the catheter to pressurize the balloon. Duringinflation, the balloon unfolds, rather than stretches. Embodiments ofthe present invention enable a balloon catheter to radially expand in avery predictable manner.

In one embodiment of the present invention, an apparatus for folding(i.e., fluting) a balloon catheter is provided. The apparatus includes abase unit, a control unit coupled to the base unit, and a power source.A plurality of arms is coupled to the base unit and arranged in a radialpattern about a central axis. The plurality of arms can translate in aradial direction toward and away from the central axis by use of aplurality of motors attached to the power source. A plurality of bladescan be attached to and detached from the plurality of arms such that theplurality of blades can engage a balloon catheter, disposed in a cavitydefined by the plurality of blades, during the folding process. Inaddition, the apparatus includes a carriage coupled to the base unit anda mounting unit disposed on the carriage for holding a balloon catheter.The carriage and mounting unit can translate in a direction generallyparallel to the central axis such that a balloon catheter is provided tothe cavity so that the balloon catheter can subsequently be folded.

A method for folding a balloon catheter is also provided. Such methodincludes the steps of providing a device having a plurality of armsarranged in a radial pattern about a central axis and capable oftranslating in a radial direction, attaching a plurality of blades tosuch plurality of arms, placing a balloon catheter on a mounting unitcoupled to a carriage, translating the carriage and the mounting unit ina direction generally parallel to the central axis so that the ballooncatheter is located within a cavity, and inflating the balloon catheter.The next steps in such method include actuating a plurality of motors tocause the plurality of blades to move in a radial direction toward theballoon catheter, moving the plurality of blades so that each of theplurality of blades contacts the inflated balloon catheter, and finallycreating a plurality of folds (i.e., flutes) on the outer surface of theinflated balloon catheter.

In another embodiment of the present balloon folding device, anapparatus for folding a balloon catheter includes a base unit and aplurality of arms coupled to the base unit. The plurality of arms isconfigured in a radial pattern about a central axis and can translate ina radial direction toward and away from the central axis. A plurality ofblades is attached to the plurality of arms and can translate with theplurality of arms so as to engage a balloon catheter during the foldingprocess. In this embodiment, a cavity is also provided which is definedby the convergence of the plurality of blades about the central axis andsuch cavity can receive a balloon catheter in order for the plurality ofblades to fold such balloon catheter.

Other embodiments of the present invention provide an apparatus forwrapping a folded balloon catheter about a catheter shaft so as tominimize the diameter of the balloon catheter. One embodiment includes abase unit, a control unit coupled to the base unit, and a power source.A plurality of arms is attached to the base unit and arranged in aradial pattern about a central axis. The plurality of arms can translatein a radial direction toward and away from the central axis by use of aplurality of motors attached to the power source. In addition, aplurality of blades can be attached to and detached from the pluralityof arms and can engage the balloon catheter during the wrapping process.A cavity defined by the plurality of blades receives a balloon catheterby way of a mounting unit coupled to a carriage. The mounting unit cantranslate in a direction generally parallel to the central axis forinserting the balloon catheter into the cavity defined by the pluralityof blades.

A method for wrapping a folded balloon catheter about a catheter shaftincludes the initial step of providing a device having a plurality ofarms configured in a radial pattern and capable of translating in aradial direction. Such method also includes the steps of attaching aplurality of blades to the plurality of arms, placing a folded ballooncatheter on a mounting unit of a carriage, translating the carriage andthe mounting unit in a direction toward a cavity defined by theplurality of blades, and actuating a plurality of motors for causing theplurality of blades to contact the balloon catheter. A final stepincludes pressing the plurality of folds on the outer surface of theballoon catheter around a catheter shaft so that the folds becomewrapped around the catheter shaft minimizing the diameter of the ballooncatheter.

In another embodiment, an apparatus for wrapping a folded ballooncatheter is provided. The apparatus includes a base unit and a pluralityof arms coupled to the base unit and arranged in a radial pattern. Theplurality of arms can translate in a radial direction toward and awayfrom a central axis. A plurality of blades is connected to the pluralityof arms for engaging a balloon catheter during the wrapping process. Inaddition, a cavity is defined by the convergence of the plurality ofblades about the central axis and can receive a balloon catheter forwrapping such balloon catheter around a catheter shaft.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the presentinvention will now be described in connection with preferred embodimentsof the invention in reference to the accompanying drawings. Theillustrated embodiments, however, are merely examples and are notintended to limit the invention. The drawings include the followingfourteen figures.

FIG. 1 is a perspective view of a balloon folding device in accordancewith a preferred embodiment of the present invention.

FIG. 2 is a perspective view of a balloon wrapping device in accordancewith a preferred embodiment of the present invention.

FIG. 3 is a perspective view of a base unit of the device including aballoon mounting feature for providing a balloon catheter to a pluralityof blades of the balloon folding device as shown in FIG. 1.

FIG. 4A is a side elevational view of the balloon mounting feature ofthe balloon folding device as shown in FIG. 3.

FIG. 4B is a side elevational view of the balloon mounting feature witha balloon catheter disposed on a carriage of the balloon mountingfeature as shown in FIG. 4A.

FIG. 5 is a partially exploded view of a base unit of the device showingan exploded arm assembly of the balloon folding device as shown in FIG.1.

FIG. 6 is a front elevational view of a base unit of the device showinga plurality of arms disposed about a central axis AA such that each ofthe plurality of arms is capable of translating toward the central axisAA in a direction A and away from the central axis AA in a direction B.

FIG. 7 is a front elevational view of a base unit of the device showinga plurality of arms and a plurality of blades disposed about a centralaxis AA such that each of the plurality of arms and each of theplurality of blades is capable of translating toward the central axis AAin a direction A and away from the central axis AA in a direction B.

FIG. 8A is a front elevational view of a three blade configuration shownin an open position about a balloon catheter of the balloon foldingdevice as shown in FIG. 1.

FIG. 8B is a front elevational view of a three blade configuration shownin a closed position creating three folds in a balloon catheter.

FIG. 9A is a front elevational view of a four blade configuration shownin an open position about a balloon catheter of the balloon foldingdevice as shown in FIG. 1.

FIG. 9B is a front elevational view of a four blade configuration shownin a closed position creating four folds in a balloon catheter.

FIG. 10A is a front elevational view of a five blade configuration shownin an open position about a balloon catheter of the balloon foldingdevice as shown in FIG. 1.

FIG. 10B is a front elevational view of a five blade configuration shownin a closed position creating five folds in a balloon catheter.

FIG. 11A is a front elevational view of a six blade configuration shownin an open position about a balloon catheter of the balloon foldingdevice as shown in FIG. 1.

FIG. 11B is a front elevational view of a six blade configuration shownin a closed position creating six folds in a balloon catheter.

FIG. 12A is a front elevational view of an eight blade configurationshown in an open position about a balloon catheter of the balloonfolding device as shown in FIG. 1.

FIG. 12B is a front elevational view of an eight blade configurationshown in a closed position creating eight folds in a balloon catheter.

FIG. 13A is a front elevational view of an exemplary eight bladeconfiguration shown in an open position of the balloon wrapping deviceas shown in FIG. 2.

FIG. 13B is a front elevational view of an exemplary eight bladeconfiguration shown in a closed position of the balloon wrapping deviceas shown in FIG. 2.

FIG. 14A is a front elevational view of an offset eight bladeconfiguration shown in an open position of the balloon wrapping deviceas shown in FIG. 2.

FIG. 14B is a front elevational view of an offset eight bladeconfiguration shown in a closed position of the balloon wrapping deviceas shown in FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The balloon catheter folding and wrapping devices described herein arecost effective tools that are particularly well suited for manufacturersof balloon catheters. These improved devices substantially speed-up,simplify, and improve the balloon folding and wrapping processes. Theballoon folding and wrapping devices described herein may be used with awide variety of balloon catheter sizes and shapes. The balloon foldingand wrapping devices are preferably provided as separate units. Eachfixture is preferably controlled by an electronic control unit.

The balloon folding and wrapping fixtures each comprise a plurality ofmovable blades which are disposed around the balloon and extend andretract in a radial direction along a linear path. The movement of theblades in the balloon folding fixture creates the folds. The movement ofthe blades in the balloon wrapping fixture wraps the folds around acatheter shaft so as to provide a small diameter. In one embodiment, theblades of the balloon folding and wrapping fixtures include built-inelectric heaters and thermocouples. These built-in heaters areadvantageously heater cartridges insertable into the blades. Anelectronic temperature controller may be provided to accurately maintainthe blade temperatures at a set value. When heated blades are usedduring folding, the balloon tends to retain its folded shape after beingremoved from the balloon folding fixture. The heated blades also heatset the folds during the wrapping process.

Advantageously, a large number of components in the folding fixture areidentical to components in the wrapping fixture. The modular nature andhigh repeatability of parts provides an important advantage by drivingdown the cost of manufacture and repair of the balloon folding deviceand the balloon wrapping device. As a result, manufactured ballooncatheters can be folded and wrapped in preparation for insertion in thehuman body at a lower cost than is available under typical folding andwrapping processes. Embodiments of the balloon folding and wrappingdevices will now be described in more detail.

As shown in FIG. 1, a balloon folding fixture 100 comprises a controlunit 110 coupled to a base unit 190. The base unit 190 includes a baseplate 130 upon which a support piece 140 is mounted thereon to providesupport to a mounting face 150. The mounting face 150 contains aplurality of arms 160, a plurality of motors 170, and a plurality ofblades 180. The plurality of blades 180 are coupled to the plurality ofarms 160 and each of the plurality of blades 180 and the plurality ofarms 160 is capable of translating in a radial direction by use of theplurality of motors 170. The plurality of motors 170 are coupled to theplurality of arms 160 and translation of each of the plurality of arms160 and plurality of blades 180 is initiated by utilizing an actuator120 that is coupled to the base unit 190. A balloon catheter is theninserted into a cavity formed by the plurality of blades 180.

In one embodiment, the balloon folding fixture 100 includes anelectronic control unit 110 for controlling the inflation of a ballooncatheter. The control unit 110 may include a pneumatic pump for applyinga vacuum to the interior of the balloon, thereby causing the foldedballoon to retain its shape after being folded.

The control unit 110 can include a motion control 112, a temperaturecontrol 114, and a pressure control 116. In addition, controls along thefront panel of the control unit 110 may allow an operator to set one ormore of the following parameters: (1) speed of the blade travel; (2)open cavity diameter in millimeters (maximum 9.5 mm on standard models,larger sizes optional) and closed cavity diameter in millimeters(minimum 0.7 mm on standard models, smaller sizes optional); (3) bladeheating ON-OFF; (4) blade temperature, preferably from ambient to 125°C. (257° F.); (5) blade dwell time; (6) blade inflation pressure; (7)balloon folding pressure; and (8) balloon vacuum.

By way of specific example, in a preferred embodiment the open andclosed cavity positions are selected with a resolution of 0.10 mm. Toprovide visual feedback, the magnitudes of individual parameters arepreferably displayed on two digital readouts and three dial gauges.Additional LED control lights indicate the part of the cycle that themachine is currently executing and which blade temperature is displayedat that particular moment. For safety reasons, all moving parts of theballoon folding fixture are preferably covered by a clear polycarbonateshield (which is not shown in FIG. 1).

In one embodiment, the balloon folding fixture 100 is configured so thatit can be used on a standard tabletop. The balloon folding device 100 ismoderately sized so that it takes up a relatively small amount of spacein a typical industrial setting. The balloon folding device 100,including the base unit 190 and the control unit 110, is portable andcan easily be transferred from one location to another location.Advantageously, such relatively compact configuration and portabilityenable a user to utilize the balloon folding fixture 100 in a widevariety of locations and settings.

FIG. 2 illustrates a balloon wrapping device 200. The balloon wrappingdevice 200 is substantially similar to the balloon folding device 100 asshown in FIG. 1. The balloon wrapping device 200 also includes a controlunit 210 and a base unit 190. The base unit 190 includes a base plate130 upon which a support piece 140 is mounted thereon to provide supportto a mounting face 150. The mounting face 150 contains a plurality ofarms 160, a plurality of motors 170, and a plurality of blades 220.

The plurality of blades 220 of the balloon wrapping device 200 areprofiled differently from the plurality of blades 180 of the balloonfolding device 100. For the folding device 100, the plurality of blades180 are profiled so as to create a plurality of folds, also known in theart as flutes, in a balloon catheter. The tips of each of the pluralityof profiled blades 180 are shaped into an interlocking profile having aconcave surface that provide a plurality of slots for holding aplurality of flutes in a balloon catheter. As a result, a fan wheelshape composed of the plurality of flutes is imparted into the foldedballoon catheter.

In the wrapping device 200, on the other hand, the plurality of blades220 are profiled so as to wrap a folded balloon catheter around acatheter shaft so as to minimize the diameter of the balloon catheter.In particular, the tips of each of the plurality of profiled blades 220are substantially flat and shaped so that the plurality of blades 220forms a substantially octagonal configuration when in a retractedposition. As the plurality of profiled blades 220 are translatedradially inward, along a linear path, such an octagonal configurationbecomes progressively smaller and will appear to form progressivelysmaller concentric circles. Advantageously, a balloon catheter with sucha wrapped configuration can be inserted into a small cavity, such aswithin the human body, with greater effectiveness than a folded ballooncatheter without a wrapped configuration.

This difference between the plurality of profiled blades 180 of theballoon folding device 100 and the plurality of blades 220 of theballoon wrapping device 200 is described in further detail below inconnection with FIGS. 8 through 14. In particular, FIGS. 8 through 12illustrate embodiments of a plurality of profiled blades 180 for aballoon folding device 100. On the other hand, FIGS. 13 and 14illustrate embodiments of a plurality of profiled blades 220 for aballoon wrapping device having an eight blade configuration.

The plurality of blades 220 are coupled to the plurality of arms 160 andeach of the plurality of blades 220 and the plurality of arms 160 iscapable of translating in a radial direction by use of the plurality ofmotors 170. The plurality of motors 170 are coupled to the plurality ofarms 160 and translation of each of the plurality of arms 160 andplurality of blades 220 is initiated by utilizing an actuator 120 thatis coupled to the base unit 190. A folded balloon catheter can beinserted into a cavity formed by the plurality of blades 220.

In one embodiment, the plurality of blades 220 is mounted to linearguides comprising ball bearings. It has been found that the use ofprecision ball bearings allows for very precise blade movement. As aresult, tight tolerances may be incorporated between each of theplurality of blades 220 for allowing the distal end portions of theblades to interlock without jamming. In another embodiment, each of theplurality of blades 220 has a built-in electric heater and thermocouple.The electric heater may comprise a removable heat cartridge. Each of theplurality of profiled blades 220 are advantageously formed from heattreated beryllium copper. Beryllium copper is preferred due to itsexcellent heat conduction, which minimizes temperature gradients alongeach of the plurality of blades 220. Accordingly, each of the pluralityof blades 220 formed of beryllium copper provides greater consistency ascompared, for example, with blades formed of stainless steel.

In one embodiment, the balloon wrapping fixture 200 comprises anelectronic control unit 210. The control unit 210 can include a motioncontrol 212 and a temperature control 214. It should be noted that thecontrol unit 210 of the balloon wrapping fixture 200 preferably does notinclude a pressure control whereas the control unit 110 of the balloonfolding fixture 100 does include a pressure control 116. This is sobecause the balloon wrapping fixture 200 operates so as to wrap a foldedballoon catheter around a catheter shaft and does not typically applypressure or a vacuum to the interior of the balloon catheter in thisembodiment.

In addition, controls along the front panel of the control unit 210 maybe provided for allowing the operator to set one or more of thefollowing parameters: (1) speed of the blade travel; (2) open cavitydiameter in millimeters (maximum 9.5 mm on standard models, larger sizesoptional) and closed cavity diameter in millimeters (minimum 0.7 mm onstandard models, smaller sizes optional); (3) blade heating ON-OFF; (4)blade temperature, preferably from ambient to 125° C. (257° F.); and (5)blade dwell time. In preferred embodiments, the open and closed cavitypositions may be selected with a resolution of 0.10 mm. To providevisual feedback, the magnitudes of individual parameters are preferablydisplayed on two digital readouts and three dial gauges. Additional LEDcontrol lights indicate the part of the cycle that the machine iscurrently executing and which blade temperature is displayed at thatparticular moment. For safety reasons, all moving parts of the balloonwrapping fixture are preferably covered by a clear polycarbonate shield(which is not shown in FIG. 2).

In general terms, the balloon wrapping fixture preferably comprises twocomponents linked by signal cables. The balloon wrapping fixture 200includes a wrapping/crimping fixture and a wrapping fixture control unit210 with LCD displays. In one preferred embodiment, the front panelcontrols allow the operator to set the maximum open cavity diameter to9.5 mm and the minimum closed cavity diameter to 0.7 mm. Additional LEDlights may be provided to indicate what part of the machine cycle iscurrently being executed as well as to provide a visual signal showingwhich blade temperature is being monitored at any given moment.

The balloon folding device 100, as shown in FIG. 1, and the balloonwrapping device 200, as shown in FIG. 2, are preferably constructed, atleast in part, from precision machined aluminum components. The machinedcomponents are preferably hard anodized to enhance surface hardness,corrosion resistance, and appearance. The folding and wrapping bladesmay be machined by a wire EDM process from heat treated berylliumcopper. This material offers an excellent combination of hardness andthermal conductivity. The folding and wrapping fixtures are configuredfor use with a wide variety of balloon types. For example, the fixturesare well suited for balloons made from materials such as nylon, PEBAX,polyurethane, and PET. However, the folding device 100 and the wrappingdevice 200 can be used with other balloon catheters as well.

One preferred embodiment of a balloon wrapping fixture 200 comprises anelectrically operated tabletop unit which employs a plurality ofradially arranged blades 220. Each of the blades includes a body portionand a tip portion. Precision stepper motor driven ball screws preferablycontrol the motion and position of the blades with 0.00025 inch (0.0064mm) resolution. The tips of the blades are preferably shaped in such away that they form a cavity of an approximately circular cross sectionwhen the blades are retracted. When the blades are retracted, the cavityhas a diameter of 0.1884 inches and is sized for receiving the foldedballoon. When the blades move inwards toward the center, this cavitybecomes progressively smaller until it collapses to a diameter of 0.03inches. Cooperation of the blades provides a smooth and uninterruptedcircumference of the cavity. As the cavity decreases in size, theballoon folds (i.e., flutes) are forced to curl around the cathetershaft in a substantially symmetrical manner. As the blades reach the endof their travel, the blades compress the folds along the catheter shaft.The blades may be held in the final position for a period of time (e.g.,10 seconds).

The blades can include heating elements. Application of heat facilitatesheat setting the folded balloon in the final wrapped position. Theblades then retract for removal of the folded and wrapped balloon. Thetip geometry allows for progressive enlargement of the cavity when theblades start moving radially away from the center of the cavity.

The following lists the specifications for preferred embodiments of aballoon wrapping fixture: (1) balloon sizes of up to 20 mm×120 mm; (2)number of blades can include 3, 4, 5, 6 or 8; (3) heat settingtemperature ranges from ambient to 125° C. (257° F.); (4) fixture sizeof 12.50″ W×13.50″ H×13.75″ D (318 mm×343 mm×349 mm); (5) control unitsize of 10.13″ W×8.50″ H×8.00″ D (257 mm×216 mm×203 mm); (6) weight ofwrapping fixture can be 9.0 to 18 lbs (4.0 to 8.2 kg); (7) control unitweight can be 8.0 lbs (3.6 kg); and (8) power requirements can rangefrom 95 to 240 VAC, 50 to 60 Hz, 60 W.

A variety of alternative blade embodiments is illustrated for use withthe balloon wrapping fixture. Several different sizes of blades areavailable both in terms of length and cavity diameters. The tip geometryallows for progressive reduction of the cavity diameter when the bladesmove radially inward toward the center of the cavity.

The general steps of folding and wrapping a balloon will now bedescribed according to one preferred method of operation. First, theballoon folding parameters and the balloon inflation pressure/vacuum areselected by the operator on the front panel of the control unit 110 thatcomes with the balloon folding device 100. In order to set the opencavity position, the balloon is pressurized, preferably to approximatelysix or seven atmospheres, and the diameter is measured, such as withcalipers. The control unit is then programmed such that the open cavityposition is slightly larger than the diameter of the balloon tofacilitate insertion of the balloon. The balloon catheter is thenmounted and inserted into the balloon folding fixture. The blades arethen actuated such that they move radially inward along a linear path toengage the outer surface of the balloon. The movement of the blades maybe controlled by a switch, such as, for example, a footswitch. As theblades moves radially inward, the blades push inward along certainlocations, thereby creating a plurality of longitudinal folds in theballoon. During movement of the blades, the pressurization mechanismswitches to a back pressure regulator which allows air to escape theballoon as it is compressed, thereby maintaining a substantiallyconstant pressure within the balloon.

The number of folds (i.e., flutes) in the balloon is equal to the numberof blades and preferably varies from three to eight blades depending onthe balloon size, balloon material, and balloon wall thickness. When theblades reach the end of their travel and the folds have been created,the pressurization mechanism then applies a negative pressure (i.e., avacuum is applied) to withdraw the remaining air from the balloon andfurther set the flutes in place. The vacuum preferably stays on for theremaining steps of the process (e.g., wrapping, etc.). To still furtherhold the folded shape, the flutes are heat-set by heated blades toenhance material shape memory.

Applying pneumatic pressure to the balloon catheter can be performed byundertaking the following steps: (1) pressurizing the balloon in orderto distend the balloon during insertion into the folding cavity; (2)maintaining a positive pressure at a set level while allowing air toescape from the balloon during folding; and (3) applying a vacuum to thefolded balloon to hold the balloon in the folded shape before it istransferred to the wrapping fixture. The pneumatic pressure process canemploy an optional air chuck and air clamp. An embodiment comprising anair chuck and air clamp is particularly well suited for fluting largespherical, un-mounted balloons. A similar pneumatic schematic withoutthe air chuck and air clamp is better suited for use with an elongateballoon.

After the folding process is completed, the folded balloon is thenremoved from the fixture and is inserted into a central cavity of aballoon wrapping fixture 200. The balloon wrapping fixture 200 utilizesa variable orifice to tightly and uniformly wrap the balloon flutesaround a catheter shaft in an efficient and predictable manner. Ifnecessary, the balloon wrapping fixture 200 may also be used to crimp astent onto the folded balloon. The balloon folding parameters as well asballoon inflation pressure/vacuum may be selected by the operator. Forexample, buttons or switches may be provided on the front panel of acontrol unit 210 that comes with each fixture. Embodiments can includecustomized versions available to handle other balloon sizes. The balloonwrapping fixture 200 is preferably provided separately from the flutingfixture 100 for enhanced modularity. The modularity allows the user topurchase only a single fixture (i.e., a fluting fixture or a wrappingfixture) without paying for features that may not be necessary, therebyproviding substantial cost savings. For example, if only stent crimpingis performed, the user may choose to purchase only the wrapping fixture.As a result, costs can be minimized by a particular user.

One preferred balloon wrapping fixture comprises eight interlockingwrapping blades. The starting diameter of the cavity is electronicallyadjusted to match the folded balloon envelope. To facilitate accurateinsertion, the folded balloon is placed on a guiding V-block that issituated in front of the cavity. The V-block preferably travels on aball bearing slide that guides the balloon into the cavity. Uponactivation of a switch, miniature stepper motors begin advancing thewrapping blades radially inward along a linear path. For addedefficiency, an actuator (e.g., footswitch) used to control the blades ofthe folding fixture may also be used to control the blades of thewrapping fixture.

As the octagon shaped cavity becomes progressively smaller, the balloonflutes are compressed inward and are forced to curl around the shaft ina symmetrical fashion. In one embodiment, the blades preferably compactthe balloon with a radial force approaching 12 lbs (53.5 N). The endposition of the blade travel is electronically set according to thecatheter shaft diameter. The balloon re-folding characteristic isenhanced by a controlled heat input into the material during thewrapping process. After reaching the end of travel, the blades stay infull contact with the compacted balloon for a period of an adjustabledwell time (e.g., 10 seconds). At the end of the cycle the blades backoff slightly so the wrapped balloon can be easily withdrawn from thecavity. It should be noted that, at any point in this process, theoperator may turn the blade heating on or off, adjust the bladetemperature from ambient to 125° C. (257° F.), and/or adjust the dwelltime.

After being withdrawn from the cavity of the balloon wrapping fixture,the wrapped balloon profile is small and very smooth since there are nosecondary creases. Furthermore, the wrapped flutes remain straight thusminimizing the possibility of material bunching during insertion intothe sheath. To preserve and protect the folded balloon, a sheath can beplaced on the balloon from either a proximal or a distal end by a simplesliding motion. Placement from the proximal end may be easier and canaccommodate tighter fitting sheaths. However, this approach shouldadvantageously be planned for early in the catheter assembly sequenceand the sheath should advantageously be placed on the shaft prior toballoon attachment. In many cases, the placement of the sheath from thedistal tip yields nearly identical results both in terms of balloonprofile and ease of installation. In various preferred embodiments, thesheath is formed of polyethylene and/or Teflon.

Finally, in a last step, the catheter luer hub is disconnected from thevacuum source. In preferred methods of use, it has been found that thetotal cycle time ranges from 15 to 40 seconds, depending on the balloontype and size. It should be noted that a large number of components inthe fluting fixture 100 are advantageously substantially similar to thecomponents in the wrapping fixture 200. The modular nature and highrepeatability of parts provides an important advantage by driving downthe cost of manufacture and repair.

The figures which follow (i.e., FIGS. 3 through 14) describe the presentinvention and its components in terms of a balloon folding fixture 100.Since embodiments of the balloon folding fixture 100 are substantiallysimilar to embodiments of the balloon wrapping fixture 200, thefollowing figures discuss embodiments of the present invention primarilyin terms of the balloon folding fixture 100. It should be appreciated,however, that these figures also show and describe features of a balloonwrapping fixture 200. As a result, the features shown in the followingfigures describe not only a balloon folding fixture 100 but alsodescribe a balloon wrapping fixture 200 of the present invention.

FIG. 3 shows a perspective view of the balloon folding device 100 with abase unit 190 and a balloon mounting feature 300. The control unit 110of the balloon folding device 100 is omitted from FIG. 3. The base unit190 of FIG. 3 is substantially similar to the base unit 190 describedabove in connection with FIG. 1. With reference to FIG. 3, to facilitatean easy and accurate insertion of either a folded balloon or a foldedballoon with a stent, a guide V-block is preferably situated in front ofthe cavity. This V-block preferably travels on a ball bearing slide andguides the catheter tip into the cavity. Precision X-Y stage withmicrometer dials allow for alignment of the catheter centerline with thecenterline of the cavity.

In one embodiment, the balloon mounting feature 300 is coupled to thebase unit 190 and the balloon mounting feature 300 allows a ballooncatheter to be inserted into a cavity formed by the plurality of blades180. The balloon mounting feature 300 preferably includes a supportcolumn 310, a motion component 320, a carriage 330, and a mounting unit340. The support column 310 comprises a lower portion 312 and an upperportion 314. In one embodiment, the lower portion 312 of the supportcolumn 310 is adjacent to at least a portion of the base plate 130 ofthe base unit 190. For example, the lower portion 312 may be attached tothe underside of the base plate 130 by a suitable fastening mechanismsuch as a bolt, screw, or adhesive. In other embodiments the supportcolumn 310 may not be adjacent the base plate 130 and could be locatedat a distance away from the base plate 130 and/or the base unit 190. Forexample, the lower portion 312 of the support column 310 could beattached to a portion of a tabletop, or other workspace area, as opposedto being attached directly to the base unit 190.

In another embodiment, the carriage 330 of the balloon mounting feature300 is coupled to at least a portion of the support column 310. Thecarriage 330 lies substantially orthogonal to the support column 310.The motion component 320 is positioned adjacent the junction of thesupport column 310 and the carriage 330, and preferably is positioned onthe underside of the carriage 330. The motion component 320 includes atleast a vertical adjustment knob 322 and a horizontal adjustment knob324. The vertical adjustment knob 322 allows a user to raise and lowerthe carriage 330 so as to permit precise alignment of the balloonmounting feature 300 in relation to the cavity defined by the pluralityof blades 180. The horizontal adjustment knob 324 permits a usertranslate the carriage 330 in a substantially horizontal direction so asto allow a balloon catheter mounted on the carriage 330 to be insertedinto the cavity defined by the plurality of blades 180.

In one mode, the carriage 330 comprises a slight recess on the upperportion of the carriage 330 and a mounting unit 340 contained thereon.As shown in FIG. 3, the mounting unit 340 can be V-shaped.Advantageously, such V-shape configuration permits a balloon catheter tobe disposed within such space defined by the V-shape configuration. As aresult, a balloon catheter can be sufficiently provided to either theballoon folding device 100 or the balloon wrapping device 200 of thepresent invention. It should be noted that the mounting unit 140 is notlimited to the V-shape configuration as shown in FIG. 3. In otherembodiments, for example, the mounting unit 140 can be configured in aU-shape, can have a square cut-out, or can have a flat top portion withno cut-out. Like methods of providing a balloon catheter to the balloonfolding device 100 can be employed.

FIGS. 4A and 4B show the balloon mounting apparatus 300 in furtherdetail. FIG. 4A illustrates the balloon mounting apparatus 300 without aballoon catheter disposed on the mounting unit 340. The motion component320 permits the carriage 330 to translate in a vertical direction Y andin a horizontal direction X. In particular, the vertical adjustment knob322 facilitates linear movement of the carriage 330 in the direction Y.On the other hand, the horizontal adjustment knob 324 facilitates linearmovement of the carriage 330 in the X direction. Such adjustment knobs322, 324 permit a user to freely move the carriage 330 so as to positionthe balloon mounting feature 300 in a desired location relative to theballoon folding device, as shown in FIG. 1, or the balloon wrappingdevice, as shown in FIG. 2.

FIG. 4B illustrates the balloon mounting apparatus 300 with a ballooncatheter 410 located on the mounting unit 340 of the carriage 330. Theballoon catheter 410 fits within the V-shape recess in the mounting unit340. Advantageously, the balloon catheter 410 can be inserted into acavity of the balloon folding device 100 so as to permit creating foldsin the exterior surface of the balloon catheter 410. In addition, thefolded balloon catheter can be inserted into a cavity of the balloonwrapping device 100 so as to permit wrapping of the balloon catheterabout a catheter shaft so as to minimize the diameter of the foldedballoon catheter.

FIG. 5 shows an embodiment of the balloon folding device 100 with apartially exploded view of an arm assembly 500. The arm assembly 500shows how the components of one of the plurality of arms 160 aresituated with respect the mounting face 150 of the base unit 190. In oneembodiment, each arm assembly 500 comprises a blade plate 510, an armbracket 520, a motor bracket 530, a coupling piece 540, a motor 550, anda blade 560. The blade plate 510 is connected to a front face of the armbracket 520. Upper fasteners 512 and lower fasteners 514 detachablyconnect the blade 560 to the blade plate 510. Advantageously, the blade560 can be detached from the blade plate 510 so as to permit differentblades having different size and configurations to be attached to theblade plate 510. As a result, a particular balloon folding device 100can employ a variety of blade sizes and shapes so as to permit folding avariety of balloon sizes and shapes.

With reference to FIG. 5, the coupling piece 540 is attached to theblade plate 510 and is capable of mating with a portion of the motor550. As a result, the coupling piece 540 connects the motor 550 to theblade plate 510 of the arm assembly 500. The motor 550 is furtherconnected to the motor bracket 530. In one embodiment, the motor bracket530 comprises a back side that is substantially orthogonal to a bottomside of the motor bracket 530. As such, the motor bracket 530 can fitsubstantially within a motor bracket recess 570 contained on themounting face 150 of the base unit 190. The motor 550 also has a wire552 that electrically couples the motor 550 to an external power source.The mounting face 150 of the base unit 190 contains an opening 580 thatallows the wire to be placed through such opening 580 so that the wirecan contact an external power source and not interfere with theoperations of the balloon folding device 100.

As described in the preceding paragraph, in one embodiment, the motorbracket 530 can attach to the mounting face 150 via a motor bracketrecess 570. In addition, the arm bracket 520 is configured to mate witha translation strip 590 disposed on the mounting face 150 of the baseunit 190. Such translation strip 590 permits the arm assembly 500 totranslate in a radial direction. As a result, the arm assembly cantranslate so as to make a cavity defined by the plurality of arms 160and the plurality of blades 180 larger or smaller depending on the needsof the user. For example, the cavity will preferably be relatively largeat one step in the balloon folding process so as to permit a ballooncatheter to be inserted into the cavity. The cavity will preferably berelatively small at another step in the folding process such as when theplurality of blades 180 engage the balloon catheter and create folds onthe surface thereof.

FIG. 6 shows a front elevational view of the base unit 190 of theballoon folding device 100. FIG. 6 includes a plurality of arms 160 anda plurality of motors 170 at least partially coupled to the mountingface 150 of the base unit 190. As shown in FIG. 6, the plurality of arms160 and the plurality of motors 170 comprise eight arms and eightmotors, respectively. Other embodiments, for example, may comprise threearms and three motors, four arms and four motors, five arms and fivemotors, six arms and six motors, or any other suitable number of armsand motors.

In one embodiment, the plurality of arms 160 are arranged symmetricallyabout a central axis AA. Each of the plurality of arms 160 is capable oftranslating in a radial direction toward the central axis AA, which isshown as direction A in FIG. 6. In addition, each of the plurality ofarms 160 is also capable of translating in a radial direction away fromthe central axis AA, which is shown as direction B in FIG. 6. Aplurality of translation strips 590, which connect each of the pluralityof arms 170 to the mounting face 150 of the base unit 190, facilitatesradial translation of each of the plurality of arms 160 relative to themounting face 150. Accordingly, the diameter of an opening 610 definedby the plurality of arms 160 can be increased or decreased bytranslating each of the plurality of arms 160 toward or away from thecentral axis AA. In particular, translating each of the plurality ofarms 160 in direction A toward the central axis AA will decrease thediameter of the opening 610. Similarly, translating each of theplurality of arms 160 in direction B away from the central axis AA willincrease the diameter of the opening 610.

In another embodiment, the plurality of motors 170 coupled to theplurality of arms 160 provides for precise radial movement. Preferably,the plurality of motors 170 comprises a plurality of stepper motorscapable of moving the plurality of arms 160 in an incremental fashionwith a high degree of precision. As a result, a user can create anopening that is precisely configured to receive, fold, and/or wrapballoon catheters of varying sizes and shapes. Advantageously, thispermits the balloon folding device 100 and the balloon wrapping device200 to be used to fold and wrap balloon catheters of a variety of sizesand shapes.

FIG. 7 shows a front elevational view of the base unit 190 of theballoon folding device 100 with a plurality of blades 170 attached tothe plurality of arms 160. As described in connection with FIG. 6, theplurality of arms 160 is capable of translating in a direction A towarda central axis AA and in a direction B away from the central axis AA.With the plurality of blades 180 attached to the plurality of arms 160,an opening 710 as shown in FIG. 7 is smaller than the opening 610 asshown in FIG. 6. The opening 710 can be configured so as to be capableof receiving a balloon catheter for either folding or wrapping suchballoon catheter. As can be seen in FIG. 7, the opening 710 isrelatively small and therefore the plurality of arms 160 and theplurality of blades 180 need only translate a relatively short distancein order to sufficiently fold a balloon catheter or wrap such foldsaround a catheter shaft. Accordingly, the precise radial movementprovided by the plurality of motors 170, preferably a plurality ofstepper motors, permits the plurality of blades 180 to engage theballoon catheter and wrap or fold such catheter with a very high degreeof precision.

With reference to FIGS. 8A and 8B, one preferred set of blades is shownfor use with the balloon folding fixture 100 comprising three profiledblades. The three blades extend and retract uniformly in a radialdirection to create three folds (i.e., flutes) in the balloon. Eachblade has a body portion 810 and a profiled tip 830 configured forforming a longitudinal fold in the balloon as the blade moves radiallyinward. An opening 820 in the body portion 810 of each blade allows theblade to be attached to and removed from at least a portion of theballoon folding device 100. It can be seen that the blades are shapedwith a particular geometry which advantageously allows the blades toextend inward in a linear direction for creating the flutes. The shapeof the profiled tip 830 allows each of the blades to extend inwardlywithout interfering with the other blades. The blades also cooperate todirect the resulting fold (i.e., flute) to one side such that it canthen be easily wrapped around the catheter.

With reference to FIG. 8B, the set of blades is shown in the extended(i.e., closed) position 800 b. It can be best seen in FIG. 8B that theblade tips 830 are shaped into an advantageous interlocking profile thatprovides three slots for holding the three flutes of the balloon andthereby imparting a fan wheel shape on the folded balloon.

As shown in FIGS. 8A and 8B, the profiled tip 830 of each of the bladeshas at least a partially concave surface relative to the ballooncatheter 802 a and the catheter shaft 804 a. The partially concavesurface on a profiled tip 830 of a particular blade is capable ofsubstantially mating with a partially convex surface of the body portion810 of an adjacent blade. However, there is preferably a slight gapbetween the concave surface of the profiled tip 830 of a particularblade and the convex surface of the body portion 810 of an adjacentblade. Such a gap provides an area for a particular flute to be createdin the balloon catheter during the balloon folding process. The size ofthe gap between adjacent blades varies; however, in one embodiment thegap is approximately 0.012 inches wide so as to house an exemplaryballoon catheter flute. As shown in FIG. 8B, a plurality of flutes 802 bis created as the plurality of blades translate radially inward toward acatheter shaft 804 b and, therefore, the balloon catheter is folded.

Each of the blades preferably moves radially inward along a linear trackduring the folding process. More particularly, the blades may beattached to ball bearing slides that provide precision guidance withlittle or no play. In the embodiment shown in FIGS. 8A and 8B, when inthe fully retracted (i.e., open) position 800 a, the set of blades formsa cavity capable of receiving a balloon catheter 802 a having a diameterof approximately 0.24 inches (5.99 mm). When in the extended (i.e.,closed) position 800 b, the diameter of the cavity is reduced tocorrespond with a catheter shaft 804 b having a diameter ofapproximately 0.055 inches (1.40 mm). Other embodiments of the threeblade fluting configuration may be dimensioned differently so as topermit the folding of either larger or smaller manufactured ballooncatheters.

In another embodiment, the three blade fluting fixture is capable ofreceiving a balloon catheter 802 a having a diameter of approximately0.177 inches (4.50 mm) and folding such balloon catheter 802 a about acatheter shaft 804 a having a diameter of approximately 0.040 inches(1.02 mm). In yet another embodiment, the three blade fluting fixturecan receive a larger balloon catheter 802 a having a diameter ofapproximately 0.315 inches (8.00 mm) and folding such balloon catheter802 a about a catheter shaft 804 a having a diameter of approximately0.070 inches (1.78 mm). Altering the shape of the body portion 810 andthe tip 830 of each of the plurality of blades in the precedingembodiment, can allow folding such balloon catheter 802 a (i.e., 0.315inch diameter) about a catheter shaft 804 a having a diameter ofapproximately 0.055 inches (1.40 mm).

Stepper motors are preferably provided for precisely controlling themovement of the blades. The stepper motors preferably control ballscrews which are capable of controlling the position of the blades towithin 0.001 inches (0.025 mm). The stepper motors may use opticalsensors for improved alignment. During use, the balloon can be foldedwith high consistency and uniformity in less than five seconds. It willbe appreciated by those skilled in the art that the present balloonfolding fixture provides a substantial improvement over existing foldingfixtures which use relatively complex and expensive pivoting blademechanisms. In one preferred embodiment, the present folding fixturetakes advantage of precision ball bearings for allowing very tighttolerances between the movable blades. The tight tolerance and precisemovement allows the blades to move in a linear manner while providingexcellent reliability.

The particular set of blades shown in FIGS. 8A and 8B is configured tocreate three longitudinal folds in the balloon. However, in alternativeconfigurations, the number of blades may vary to create a differentnumber of flutes. For example, in various alternative embodiments, theballoon can be folded into three, four, five, six or eight flutes. Thefolding blades may be provided with different lengths for accommodatingballoons of different sizes. For example, the present invention may beused with balloons having lengths ranging from approximately 1 cm to 14cm long. Preferred folding blades can handle balloons having diametersfrom approximately 1.5 mm to 20 mm. It should be appreciated thatseveral different sizes of blades are available both in terms of length,number of flutes, and the catheter shaft diameter.

Preferably, the balloon folding fixture is equipped with heated blades.Using heated blades, the folded balloon is heat-set and a vacuum isapplied to lock the folds in place. As shown in FIGS. 8A and 8B, eachblade may be formed with an opening 820 or other receptacle forreceiving a heating unit.

FIG. 9A illustrates a four blade embodiment with the blades in an openposition 900 a. Similar to the previously described embodiments, eachblade has a body portion 910, a profiled tip portion 930, and an opening920 in the body portion 910 of the blade. FIG. 9B shows the four bladeembodiment in a closed position 900 b so as to create four folds in aballoon catheter.

The profiled tip 930 of each of the four blades has at least a partiallyconcave surface relative to the balloon catheter 902 a and the cathetershaft 904 a. The partially concave surface on a profiled tip 930 of aparticular blade is capable of substantially mating with a partiallyconvex surface of the body portion 910 of an adjacent blade. However,there is preferably a slight gap between the concave surface of theprofiled tip 930 of a particular blade and the convex surface of thebody portion 910 of an adjacent blade. Such a gap provides an area for aparticular flute to be created in the balloon catheter during theballoon folding process. The size of the gap between adjacent bladesvaries; however, in one embodiment the gap is approximately 0.012 incheswide so as to house an exemplary balloon catheter flute. As shown inFIG. 9B, four flutes 902 b are created as the four blades translateradially inward toward a catheter shaft 904 b and, therefore, theballoon catheter is folded.

In one embodiment of the four blade configuration, the device is capableof receiving a balloon catheter 902 a having a diameter ranging fromapproximately 3.0 mm to 12.0 mm. When in the closed position, as shownin FIG. 9B, the four blade device preferably folds the balloon catheter902 a about a catheter shaft having a diameter ranging from 0.075 inchesto 0.100 inches so as to create four flutes 902 b in the manufacturedballoon catheter 902 a. However, the four blade configuration is notlimited to this particular embodiment and may include profiled blades ofa variety of sizes and shapes so as to be capable of receiving a varietyof sizes and shapes of balloon catheters and catheter shafts.

FIG. 10A illustrates a five blade embodiment with the blades in an openposition 1000 a. Similar to the previously described embodiments, eachblade has a body portion 1010, a profiled tip portion 1030, and anopening 1020 in the body portion 1010 of the blade. FIG. 10B shows thefive blade embodiment in a closed position 1000 b so as to create fivefolds in a balloon catheter.

Similar to the three blade and four blade embodiments described above inconnection with FIGS. 8 and 9, respectively, the five blade embodimenthas blades having profiled tips 1030 having at least partially concavesurfaces so as to substantially mate with partially convex surfaces ofthe body portions 1010 leaving five slight gaps for housing five flutesduring the balloon catheter folding process.

In the embodiment shown in FIGS. 10A and 10B, the five blade device iscapable of receiving a balloon catheter 1002 a having a diameter ofapproximately 0.79 inches (19.99 mm) and folding such balloon catheter1002 a about a catheter shaft 1004 b having a diameter ranging fromapproximately 0.090 inches to 0.100 inches. However, the five bladeconfiguration is not limited to this particular embodiment and mayinclude profiled blades of a variety of sizes and shapes so as to becapable of receiving a variety of sizes and shapes of balloon cathetersand catheter shafts.

FIG. 11A illustrates a six blade embodiment with the blades in an openposition 1100 a. Similar to the previously described embodiments, eachblade has a body portion 1110, a profiled tip portion 1130, and anopening 1120 in the body portion 1110 of the blade. FIG. 11B shows thesix blade embodiment in a closed position 1100 b so as to create sixfolds in a balloon catheter.

Similar to the embodiments described above, the six blade embodiment hasblades having profiled tips 1130 having at least partially concavesurfaces so as to substantially mate with partially convex surfaces ofthe body portions 1110 leaving six slight gaps for housing six flutesduring the balloon catheter folding process.

In the embodiment shown in FIGS. 11A and 11B, the six blade device iscapable of receiving a balloon catheter 1102 a having a diameter ofapproximately 0.39 inches (10.01 mm) and folding such balloon catheter1102 a about a catheter shaft 1104 b having a diameter ranging fromapproximately 0.075 inches to 0.090 inches. However, the six bladeconfiguration is not limited to this particular embodiment and mayinclude profiled blades of a variety of sizes and shapes so as to becapable of receiving a variety of sizes and shapes of balloon cathetersand catheter shafts.

FIG. 12A illustrates an eight blade embodiment with the blades in anopen position 1200 a. Similar to the previously described embodiments,each blade has a body portion 1210, a profiled tip portion 1230, and anopening 1220 in the body portion 1210 of the blade. FIG. 12B shows theeight blade embodiment in a closed position 1200 b so as to create eightfolds in a balloon catheter.

Similar to the embodiments described above, the eight blade embodimenthas blades having profiled tips 1230 having at least partially concavesurfaces so as to substantially mate with partially convex surfaces ofthe body portions 1210 leaving eight slight gaps for housing eightflutes during the balloon catheter folding process. In addition, theeight blade embodiment preferably has a body portion 1210 that has aV-like configuration so as to permit the eight blades to translatesimultaneously radially inward without having any particular bladeinterfere with such uniform radial movement.

Configurations of the eight blade embodiment are more limited than, forexample, the three blade embodiment because there is less open spacebetween adjacent blades in the eight blade embodiment. As a result, aneight blade embodiment having blades with a substantially straight bodyportion 1210 would not permit the blades to translate radially inward soas to flute a balloon catheter because the blades would prematurelycontact each other and prevent radial translation. However, it should benoted that the eight blade configuration is not limited to the specificV-like configuration as shown in FIGS. 12A and 12B and may includeprofiled blades of a variety of sizes and shapes so as to be capable ofreceiving a variety of sizes and shapes of balloon catheters andcatheter shafts.

The blades of an exemplary balloon wrapping device will now be describedin connection with FIGS. 13 and 14. With reference to FIGS. 13A and 13B,an end view of a balloon wrapping fixture incorporating a set of eightblades is shown. In FIG. 13A, the blades are in the retracted (i.e.,open) position 1300 a for receiving a folded balloon. FIG. 13Billustrates the set of blades of in the extended (i.e., closed) position1300 b. It should be noted that in one embodiment of the balloonwrapping device, a stent can be crimped onto the exterior of theballoon.

As shown in FIG. 13A, the embodiment comprises a device having eightprofiled blades. For a balloon wrapping fixture, eight profiled bladesare preferable because such a configuration has been found to be capableof sufficiently wrapping a fluted balloon catheter about a cathetershaft. Having less than eight profiled blades increases the possibilitythat gaps may be left in the wrapped balloon since the tips of threeblades, for example, might not be capable of substantially wrapping afolded balloon about a round catheter shaft. Having more than eightprofiled blades could be advantageous since such a system would likelycreate an opening closer to a round opening for wrapping a foldedballoon about a round catheter shaft. However, as the number of bladesincreases, there is a greater possibility that adjacent blades willcontact each other and interfere with inward radial translation of theset of blades. As a result, an eight blade configuration provides aballoon wrapping device with a proper balance between having an openingthat will conform to a round balloon catheter shaft and minimizinginterference of adjacent blades so as to permit uniform inward radiallytranslation.

Each of the blades includes a body portion 1310, an opening 1320, and aprofiled tip 1330. The tip geometry of the profiled tips 1330 allows forprogressive reduction of the cavity diameter when the blades moveradially inward toward the center of the cavity. As a result, when in anopen position 1302 a, the blades receive a folded balloon catheter. Inthis configuration, the plurality of blade tips 1330 substantially formsan octagon. As the blades move radially inward, the octagonal opening1302 a becomes progressively smaller. When in a closed position 1302 b,the blades wrap a folded balloon catheter around a catheter shaft so asto minimize the diameter of the balloon catheter. In a closed position1302 b, the plurality of blade tips 1330 substantially form a circlethat wraps the folded balloon catheter around a circular catheter shaft.

Each of the profiled blades preferably moves radially inward along alinear track during the wrapping process. More particularly, the bladesmay be attached to ball bearing slides that provide precision guidancewith little or no play. Stepper motors are preferably provided forprecisely controlling the movement of the blades. The stepper motorspreferably control ball screws which are capable of controlling theposition of the blades to within 0.001 inches (0.025 mm). The steppermotors may use optical sensors for improved alignment. Advantageously,the balloon can be wrapped with high consistency and uniformity in lessthan five seconds. It will be appreciated by those skilled in the artthat the present balloon wrapping fixture provides a substantialimprovement over existing wrapping fixtures which use relatively complexand expensive pivoting blade mechanisms.

Preferably, the balloon folding fixture is equipped with heated blades.Using heated blades, the folded balloon is heat-set and a vacuum isapplied to lock the folds in place. As shown in FIGS. 13A and 13B, eachblade may be formed with an opening 1320 or other receptacle forreceiving a heating unit. In another embodiment, the opening 1320 itselfmay comprise a heating element for heating the profiled blades of theballoon wrapping device.

The size and shape of the profiled blades varies among embodiments. Inone embodiment, the balloon wrapping fixture receives a small foldedballoon catheter. In such embodiment, the profiled blades can open to amaximum diameter of approximately 0.1884 inches and can close to aminimum diameter of approximately 0.0300 inches. In another embodiment,the profiled blades can receive a medium-sized balloon catheter suchthat the blades can open to a maximum diameter of approximately 0.2637inches and can close to a minimum diameter of approximately 0.0400inches. In yet another embodiment, the profiled blades of the balloonwrapping device can receive a large folded balloon catheter. In thisembodiment, the blades retract to an open position having a maximumdiameter of approximately 0.3761 inches and close to a closed positionhaving a minimum diameter of approximately 0.0400 inches.

FIGS. 14A and 14B show an eight blade configuration for a balloonwrapping device, wherein such blades have an offset in their body so asto permit the blades to sufficiently interlock with each other when inthe closed position 1400 b. In FIG. 14A, the blades are in the retracted(i.e., open) position 1400 a for receiving a folded balloon. FIG. 14Billustrates the set of blades of in the extended (i.e., closed) position1400 b. It should be noted that a stent can be crimped onto the exteriorof the balloon.

The body portion 1410 of the blade in FIGS. 14A and 14B includes anangled offset so that adjacent blades can sufficiently mate with eachother when the eight blades are translated radially inward. Suchembodiment provides an alternative embodiment to the straight bodiedblades shown in FIGS. 13A and 13B. Similar to the wrapping blades shownin FIGS. 13A and 13B, the wrapping blades shown in FIGS. 14A and 14Bhave profiled tips 1430 with a substantially flat configuration. As aresult, the tip geometry of the profiled tips 1430 allows forprogressive reduction of the cavity diameter when the blades moveradially inward toward the center of the cavity.

When in an open position 1400 a, the blades receive a folded ballooncatheter. In this configuration, the plurality of blade tips 1430substantially forms an octagon. As the blades move radially inward, theoctagonal opening 1402 a becomes progressively smaller. When in a closedposition 1400 b, the blades wrap a folded balloon catheter around acatheter shaft so as to minimize the diameter of the balloon catheter.In a closed position 1400 b, the plurality of blade tips 1430substantially form a circle that wraps the folded balloon catheteraround a circular catheter shaft.

Preferably, the balloon folding fixture having offset blades is equippedwith heated blades. As shown in FIGS. 14A and 14B, each blade may beformed with an opening 1420 or other receptacle for receiving a heatingunit. In another embodiment, the opening 1420 itself may comprise aheating element for heating the profiled blades of the balloon wrappingdevice.

The above presents a description of the best mode contemplated forcarrying out the present balloon folding and wrapping devices andmethods, and of the manner and process of making and using them, in suchfull, clear, concise, and exact terms as to enable any person skilled inthe art to which it pertains to make and use these devices and methods.These balloon folding and wrapping devices and methods are, however,susceptible to modifications and alternative method steps from thosediscussed above that are fully equivalent. Consequently, these balloonfolding and wrapping devices and methods are not limited to theparticular embodiments disclosed. On the contrary, these balloon foldingand wrapping devices and methods cover all modifications and alternativeconstructions and methods coming within the spirit and scope of thepresent invention.

1. A balloon folding apparatus, comprising: a base unit; a control unitcoupled to the base unit; a power source; a plurality of arms coupled tothe base unit and configured in a radial pattern converging toward acentral axis, wherein the plurality of arms is capable of translating ina radial direction; a plurality of motors coupled to the power sourcefor enabling the plurality of arms to translate in a radial direction; aplurality of blades capable of being attached to and detached from theplurality of arms, wherein the plurality of blades is capable oftranslating in a radial direction and engaging a balloon catheter duringthe folding process; a cavity defined by the convergence of theplurality of blades about the central axis, wherein the cavity iscapable of receiving a balloon catheter; a carriage coupled to the baseunit and disposed substantially near the central axis, wherein thecarriage is capable of translating in a direction generally parallel tothe central axis; and a mounting unit coupled to the carriage, whereinthe mounting unit is capable of holding a balloon catheter and providingthe balloon catheter to the cavity for engagement by the plurality ofblades.
 2. The balloon folding apparatus of claim 1, wherein the controlunit is capable of controlling the inflation of the balloon catheter. 3.The balloon folding apparatus of claim 1, wherein the control unitfurther comprises a pump for applying a vacuum to the interior of theballoon catheter which facilitates holding the shape of the ballooncatheter after the folding process.
 4. The balloon folding apparatus ofclaim 1 further comprising a plurality of receiving rods disposed atleast partially on the plurality of arms.
 5. The balloon foldingapparatus of claim 4 further comprising a plurality of cylindricalcavities disposed on the plurality of blades for attaching the pluralityof blades to the plurality of receiving rods.
 6. The balloon foldingapparatus of claim 1, wherein the plurality of motors comprises aplurality of stepper motors for providing precise radial movement of theplurality of arms.
 7. The balloon folding apparatus of claim 1, whereineach of the plurality of blades is mounted to linear guides comprisingball bearings.
 8. The balloon folding apparatus of claim 1, wherein eachof the plurality of blades is composed of heat treated beryllium copper.9. The balloon folding apparatus of claim 1, wherein each of theplurality of blades has an integrated electric heater.
 10. The balloonfolding apparatus of claim 1, wherein each of the plurality of bladeshas an integrated thermocouple.
 11. The balloon folding apparatus ofclaim 1, wherein the plurality of blades comprises three blades.
 12. Theballoon folding apparatus of claim 1, wherein the plurality of bladescomprises four blades.
 13. The balloon folding apparatus of claim 1,wherein the plurality of blades comprises five blades.
 14. The balloonfolding apparatus of claim 1, wherein the plurality of blades comprisessix blades.
 15. The balloon folding apparatus of claim 1, wherein theplurality of blades comprises eight blades.
 16. A balloon wrappingapparatus, comprising: a base unit; a control unit coupled to the baseunit; a power source; a plurality of arms coupled to the base unit andconfigured in a radial pattern converging toward a central axis, whereinthe plurality of arms is capable of translating in a radial direction; aplurality of motors coupled to the power source for enabling theplurality of arms to translate in a radial direction; a plurality ofblades capable of being attached to and detached from the plurality ofarms, wherein the plurality of blades is capable of translating in aradial direction and engaging a balloon catheter during the wrappingprocess; a cavity defined by the convergence of the plurality of bladesabout the central axis, wherein the cavity is capable of receiving aballoon catheter; a carriage coupled to the base unit and disposedsubstantially near the central axis, wherein the carriage is capable oftranslating in a direction generally parallel to the central axis; and amounting unit coupled to the carriage, wherein the mounting unit iscapable of holding a balloon catheter and providing the balloon catheterto the cavity for engagement by the plurality of blades.
 17. The balloonwrapping apparatus of claim 16, wherein the control unit furthercomprises a pump for applying a vacuum to the interior of the ballooncatheter which facilitates holding the shape of the balloon catheterafter the wrapping process.
 18. The balloon wrapping apparatus of claim16 further comprising a plurality of receiving rods disposed at leastpartially on the plurality of arms.
 19. The balloon wrapping apparatusof claim 18 further comprising a plurality of cylindrical cavitiesdisposed on the plurality of blades for attaching the plurality ofblades to the plurality of receiving rods.
 20. The balloon wrappingapparatus of claim 16, wherein the plurality of motors comprises aplurality of stepper motors for providing precise radial movement of theplurality of arms.
 21. The balloon wrapping apparatus of claim 16,wherein each of the plurality of blades is mounted to linear guidescomprising ball bearings.
 22. The balloon wrapping apparatus of claim16, wherein each of the plurality of blades is composed of heat treatedberyllium copper.
 23. The balloon wrapping apparatus of claim 16,wherein each of the plurality of blades has an integrated electricheater.
 24. The balloon wrapping apparatus of claim 16, wherein each ofthe plurality of blades has an integrated thermocouple.
 25. The balloonwrapping apparatus of claim 16, wherein the plurality of bladescomprises three blades.
 26. The balloon wrapping apparatus of claim 16,wherein the plurality of blades comprises four blades.
 27. The balloonwrapping apparatus of claim 16, wherein the plurality of bladescomprises five blades.
 28. The balloon wrapping apparatus of claim 16,wherein the plurality of blades comprises six blades.
 29. The balloonwrapping apparatus of claim 16, wherein the plurality of bladescomprises eight blades.